There are 2 utilizations factored into your score:
1) revolving (CCs, most charge cards, and some HELOCs or LOCs)
2) installment (SLs, mortgages, car, etc.)
Installment and revolving utilizations are never ever combined for scoring but both are factored into the score individually.
Collections (CAs), public records (e.g. judgments, BKs, etc.), and non-CC COs are never ever factoried into utilization.
Revolving utilization weighs a whole lot BIGGER than installment utilization. We don't know exactly by how much, but I'd guess a minimum of 95% of utilization in scoring is revolving. In other words, if you pay your loans from an org. $10k balance to $50, you may not see too much of an increase; single points at best, if at all. On the flip side, if you paid $10k on your CCs with a CL of $10k, down to $50, you'd likely have a 100 point gain.
IMO, ignore installment utilization. BTW, once a loan reaches $0, its balance and org. limit are removed from the utilization portion of scoring (and your mix of credit). Beside you can't do anything about it anyway, other than eventually pay it off.
Revolving utilization is a big part of scoring as mentioned. All open CCs, HELOCs and LOCs with a marginal limit (I think $50k, YMMV), and some charged-off CCs are factored together into revolving utilization. Utilization is calculated by dividing the balance into the reported credit limit. If ever in doubt about your calculations, you may often find the utilization percentage listed on pages 2 or 3 of your FICO report.
FICO looks at individual utilization, the CC status, your scoring bucket, and your mix of credit when factoring in a score for utilization. Ideally for max points, you'd want all but one or at the most 1/2 of your CCs reporting $0 at all times with the remainder below 9%. The status comes into play with closed accounts. CCs carrying a balance AND closed are still factored into utilization. Once the CC reaches $0, then the card is removed from consideration never to be used in utilization again (unless reopened). Your scoring bucket plays a big part into how many points come back, but I won't dive into that now. Finally, your mix of credit is a big, big part of that utilization calculation. While the utilization percentages are equal, someone with only 1 CC who brings their utilization from 100% to 5%, for example, will NOT gain as many points as someone with 5 CCs and does the same. Ideally your mix should be two or more revolving and one charge card (e.g. store).
Bringing all CCs to $0 can actually hurt your score. Always let a balance report on at least 1 CC.
CCs are easy to figure. Look at the balance and divide it into the credit limit. Some reported CCs or charge accounts don't report a CL. For example, I have a Macys special event account and the CL is $2500 on EQ and EX. But on TU, the CL isn't reported. TU reads the "high balance" as the CL when considering utilization, in this example. Some CCs, like an Amex Green, are NOT factored into utilization at all. They are specially coded because you can't carry a balance and must PIF monthly.
FICO will ding you extra good if you ever carry your CC balance over the limit. There's an extra penalty and I've been hit with that once in the past for 20 points or so.
Some HELOCs and LOCs are factored into revolving utilization. Again, it is based on the limit and I think TU has some special considerations regarding what the limit is.
CC COs are usually factored into the revolving utilization. YMMV based on the age of the DOFD and the baddie itself. Not all CC COs are factored in, but DW had one with CapOne. Her balance forever climbed past $750 with an org. CL of $250. Once CRA read it via the CL. Another read the reported "high limit". If you have CC COs, factor in the CC CL first and plug the numbers until you can get your % to match with the one on your FICO report. Many report large increases when they PIF a CC CO.
Examples.....
Visa $120 balance with a $500 CL
Visa $832 balance with a $750 CL
MC $4356 balance with a $6000 CL
Store charge $0 balance with a $2500 CL
LOC $0 balance with a $500 CL
CC CO $932 balance with a $500 CL, assuming it is factored in.
In this example, your total balances are $6240 and your CLs are $10750. Your overall utilization is 58%. That's not too good. In fact you have individual utilizations that far exceed 58%. I bet you are getting dinged, in this example, by 20 pts for being OTL. Plus you are getting hit for at least 60 points for the large utilization. If you paid everything and let $50 or so report on the MC, then you'll see at least 80 points.
Paying down utilization is usually the fastest way (and most expensive for many) to bring down your score.
